Conventionally, the humidity control apparatus of JP-A No. 2005-291570, in which an adsorption heat exchanger carrying an adsorbent that adsorbs moisture is connected to a refrigerant circuit, is known. This humidity control apparatus is capable of switching between a dehumidifying operation and a humidifying operation due to the above-described adsorption heat exchanger functioning as an evaporator or a condenser as a result of switching the circulation direction of the refrigerant. For example, in the dehumidifying operation, the adsorbent is cooled by the refrigerant that evaporates in the adsorption heat exchanger and moisture in the air is adsorbed on this adsorbent. The air that has imparted its moisture to the adsorbent and been dehumidified is supplied to a room and the room is dehumidified. On the other hand, in the humidifying operation, the adsorbent is heated by the refrigerant that condenses in the adsorption heat exchanger and the moisture adsorbed on the adsorbent is desorbed. The air that contains this moisture and has been humidified is supplied to the room and the room is humidified.
Further, in JP-A No. 2003-106609, an air conditioner in which refrigerant circulates in a refrigerant circuit and which performs a vapor compression refrigeration cycle is disclosed. A compressor, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger, and a four-way switching valve are connected to the refrigerant circuit of this air conditioner. This air conditioner is capable of reversing the circulation direction of the refrigerant by switching the four-way switching valve, and the air conditioner is capable of switching between a cooling operation and a heating operation. For example, in the cooling operation, air cooled in the indoor heat exchanger that works as an evaporator is supplied to a room and the room is cooled. On the other hand, in the heating operation, air heated in the indoor heat exchanger that works as a condenser is supplied to the room and the room is heated.
Generally, the air conditioning load of the entire control target space includes the latent heat load and the sensible heat load. Considering a case where the humidity control apparatus of JP-A No. 2005-291570 and the air conditioner of JP-A No. 2003-106609 are installed in the same space and made to perform latent heat processing and sensible heat processing, the humidity control apparatus and the air conditioner can both perform latent heat processing, which is air conditioning processing for the latent heat load, and sensible heat processing, which is air conditioning processing for the sensible heat load. For this reason, it can be said that the sum of the latent heat throughput processed by the humidity control apparatus and the latent heat throughput processed by the air conditioner is equal to the latent heat load of the entire space and that the sum of the sensible heat throughput processed by the humidity control apparatus and the sensible heat throughput processed by the air conditioner is equal to the sensible heat load of the entire space.